DogfightOut director Joe Mantello yanks the leash of this very promising world premiere musical based on a 1991 indie about a homely waitress (Lindsay Mendez) who bonds with a handsome Vietnam-bound Marine (Derek Klena) after a party in which the jarheads compete to invite the ugliest date — cue crossdressing sight gag! Benj Pasek and Justin Paul’s score is memorably rousing, but Peter Duchan’s book has more bark than bite.Second Stage Theatre, through August 12.